The tiger of Koutou. The chief of the Chousa region.
Descendent of the great strategist Sonbu (Sun Tzu), and a capable person himself too. Holds the legendary sword "Koteitou", a sword which is on par with the "Ryuuteiken".

Sonken Zephyranthes and the Chousa Four Riders also took part in the battle at the Korou fortress where he died while shielding his daughter from Ryofu's attack.
The 'Armor of Byako (白虎の鎧)', the armor that was passed down by the founder Sonbu and also the armor which Sonken Zephyranthes always have on is later passed on to his son Sonken.
In the Comic World version Gou appears to be already under orders of Sonken, his son. There he appears to entrust the Shin Koteitou to his son.
In the Brave Battle Warriors anime, he and his army fought bravely to seize the Koroukan (虎牢関). He also led his army to pursue Toutaku after seeing Rakuyou in flames. While in pursuit, Ryofu intervened, and killed him. In his final words, he told Sonken that he will one day inherit the Koteitou.